1. Field of the Invention
The present invention is directed to a device for deploying an antenna from a stowed position to an open deployed position. More particularly, the present invention is directed to deploying mechanisms for deploying antennas on top of a microcell which is located at the top of a tower.
2. Description of the Background Art
Standard cell site equipment is typically installed in a small block house located adjacent to a tower on which cell site antennas are mounted. The cell site radios in the block house is connected to the cell site antennas typically through hundreds of feet of coaxial cable. This arrangement produces a loss of a significant portion of the radio energy which is dissipated through the coaxial cable.
The antennas for a cell site often include a single omnidirectional whip antenna for transmitting and receiving signals, and an additional similar omnidirectional whip antenna for receiving signals. The second receive antenna is spaced some distance from the first antenna in order to provide space diversity, which ameliorates the effects of multipath fading. Multipath fading is a phenomenon in which radio signals transmitted over a large distance are received directly from the source as well as indirectly from reflected surfaces such as buildings, hills, lakes, etc. The multiple signals can combine in such a way that at certain times, the signals cancel each other, so that a highly attenuated signal is received. Spacing two receive antennas several wavelengths apart diminishes the signal fading.
The present invention is directed to a system for deploying an antenna from a stowed position to a deployed position on a tower frame having a lower section and an upper section. A carrier supporting the antenna is moveable relative to the tower frame in a direction toward the upper section, and the antenna is deployed from the stowed position to the deployed position when the carrier reaches the upper section of the tower frame.
For example, an antenna deploying mechanism moves the antennas from a stowed position within the confines of the tower structure while a microcell carrying the antennas is being raised or lowered, to a deployed position outside of the confines of the tower structure when the microcell reaches the top of the tower. The deployment can be accomplished without additional motors to move the antennas into position. Instead, the deployment mechanism can use the upward motion of the microcell provided by a winch to move the antennas from the stowed position to the deployed position. Similarly, lowering of the microcell by the winch can cause the antennas to automatically move from the deployed position to the stowed position within the confines of the tower structure.